text: // SPDX-License-Identifier: GPL-2.0
  
  #include <asm/neon.h>
  #include <asm/simd.h>
  #include <crypto/sm4.h>
  #include <linux/module.h>
  #include <linux/cpufeature.h>
  #include <linux/crypto.h>
  #include <linux/types.h>
  
  MODULE_ALIAS_CRYPTO("sm4");
  MODULE_ALIAS_CRYPTO("sm4-ce");
  MODULE_DESCRIPTION("SM4 symmetric cipher using ARMv8 Crypto Extensions");
  MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  MODULE_LICENSE("GPL v2");
  
  asmlinkage void sm4_ce_do_crypt(const u32 *rk, void *out, const void *in);
  
  static void sm4_ce_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  {
  	const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm);
  
  	if (!may_use_simd()) {
  		crypto_sm4_encrypt(tfm, out, in);
  	} else {
  		kernel_neon_begin();
  		sm4_ce_do_crypt(ctx->rkey_enc, out, in);
  		kernel_neon_end();
  	}
  }
  
  static void sm4_ce_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  {
  	const struct crypto_sm4_ctx *ctx = crypto_tfm_ctx(tfm);
  
  	if (!may_use_simd()) {
  		crypto_sm4_decrypt(tfm, out, in);
  	} else {
  		kernel_neon_begin();
  		sm4_ce_do_crypt(ctx->rkey_dec, out, in);
  		kernel_neon_end();
  	}
  }
  
  static struct crypto_alg sm4_ce_alg = {
  	.cra_name			= "sm4",
  	.cra_driver_name		= "sm4-ce",
  	.cra_priority			= 200,
  	.cra_flags			= CRYPTO_ALG_TYPE_CIPHER,
  	.cra_blocksize			= SM4_BLOCK_SIZE,
  	.cra_ctxsize			= sizeof(struct crypto_sm4_ctx),
  	.cra_module			= THIS_MODULE,
  	.cra_u.cipher = {
  		.cia_min_keysize	= SM4_KEY_SIZE,
  		.cia_max_keysize	= SM4_KEY_SIZE,
  		.cia_setkey		= crypto_sm4_set_key,
  		.cia_encrypt		= sm4_ce_encrypt,
  		.cia_decrypt		= sm4_ce_decrypt
  	}
  };
  
  static int __init sm4_ce_mod_init(void)
  {
  	return crypto_register_alg(&sm4_ce_alg);
  }
  
  static void __exit sm4_ce_mod_fini(void)
  {
  	crypto_unregister_alg(&sm4_ce_alg);
  }
  
  module_cpu_feature_match(SM3, sm4_ce_mod_init);
  module_exit(sm4_ce_mod_fini);
  